Berger et al [“Nanometers, Picowatts, Femtojoules: Thermal Analysis and Optical Spectroscopy Using Micromechanics,” Analytical Methods & Instrumentation, Special Issue, uTAS '96] disclose examples of low-cost, disposable MEMS devices which perform optical absorption spectra, calorimetric and thermal analysis, electrochemical stressograms, gas phase adsorption and surface reaction monitors.
Cantilevers are used in atomic force microprobes which are able to move at high speed Minne et al [“Automated parallel high-speed atomic force microscopy,” Applied Physics Letters, Volume 78, No. 18, May 4, 1998] also describe multiple atomic force microprobes operating in parallel for use in an atomic force microscope.
Manalis et al [“Interdigital cantilevers for atomic force microscopy,” Applied Physics Letters, Vol. 69, No. 25, Dec. 16, 1996], disclose an atomic force microscopy (AFM) sensor in which a silicon cantilever is micromachined into the shape of interdigitated fingers that form a diffraction grating which allows the cantilever displacement to be determined by measuring the intensity of diffracted modes.
Lang et al [“Sequential position readout from arrays of micromechanical cantilever sensors,” Applied Physics Letters, Vol. 73, p. 383, 1998] describe a reference cantilever for canceling environmental noise, where chemically specific responses are extracted statically in a noisy environment using a sensor cantilever to detect specific chemical interactions and an uncoated cantilever as a reference.
A conventional method for determining cell motility is also known in the art. In U.S. Pat. No. 6,238,874 entitled “Cell Motility Assay” a detection scheme is described which involves positioning a labeled fluorescence marker on a specimen and measuring its motion through the use of an excitation radiation source and radiation optics.
Prior art cantilever deflection sensors require cumbersome manipulation, for example, by use of mechanical stages, and use of optical alignment of a laser beam and a position-sensitive detector relative to the cantilever. Such manipulation and alignment is time consuming and increases the complexity of the system operation, which increases costs by requiring trained technicians to operate the system.
Although cantilevers have been known for many years, they have never before been applied to determining the miniscule motion of specimens in fluids, of great interest to biology and other technologies.